As someone who has played almost every day for the past year and poured $1700+ into my Standard and Historic collections, the Alchemy changes in Historic make me regret ever playing Arena. Out of 20+ Historic decks only two were playable without swapping for rebalanced Alchemy cards, when they're not even the most broken cards in the format.
I got into Historic because I was a kitchen table player in paper and wanted a more challenging and interesting format closer to what I was use to without using the unsightly and annoyingly cumbersome MTGO platform. Now I can't even escape to Historic when Standard is boring me. Alchemy is fine if you want to spice up Standard, but keep it out of Historic.